The frames were originally 640 x 480. The material used was a stock Bryce texture -- I dont remember exactly which one, but its a grey cloud texture. It all depends on what kind of light is hitting it: some respond better than others to multiple light sources, while a few are more content with only one or two beyond ambient -- shortly after this, I tried doing the same thing to show a smoke effect for the war scene in Candide (the musical adaptation), and I wound up having to create a whole new texture in the Texture Editor. Experiment; thats the best I can recommend.